Han Kangbo 韓康伯 (332-380), personal name (ming) Han Bo 韓伯, was a philosopher and Confucian scholar of the Eastern Jin period 東晉 (317-420). He came from a poor family in Changshe 長社 (modern Changge 長葛, Henan) but showed extraordinary intelligence. During the reign of Emperor Jianwen 簡文帝 (r. 371-372) he was invited for a court discussion and was appointed to the office of attendant in the Imperial Secretariat (zhongshu lang 中書郎), later cavalier attendant-in-ordinary (sanji changshi 散騎常侍), Minister of Personnel (libu shangshu 吏部尚書) and General of the Palace Guard (lingjun jiangjun 領軍將軍).
Han Kangbo was an adherent of the so-called "School of the Mystery" (xuanxue 玄學), an offspring of Daoism that supposed that the voidness (wu 無, dimensionless, another term for Dao 道, the "Way") was the fundament of the world. This voidness was seen as the analogon to the "highest extreme" (taiji 太極, infinity) mentioned in the Yijing 易經 "Book of Changes". The voidness or the highest extreme produce the two effects (liang yi 兩儀, i. e. Yin and Yang 陰陽). Taiji is a name for the "unnameable" (wu cheng zhi cheng 無稱之稱), and a designation for something that can not be touched. The designation "highest extreme" means that the Dao permeates everything in the world, and there is nothing that is not filled with the spirit of the Dao. The Dao itself is the absolute motionlessness, and cannot be seen, at least not as a separate entity. Instead, the Dao can be perceived everywhere in all actions and thoughts. This theory is called guiwulun "the appraisal of the Nothing". Han Kangbo was also influenced by Guo Xiang's 郭象 theory of the duhualun 獨化論 "solitary transformation", which described the process from "nothing" (wu 無) to "existing" (you 有). All things come into being by a spontaneous movement of the two effects or energies Yin and Yang. There is nothing like a creator, but things come into being out of themselves, inmidst the great voidness (da xu 大虛). Han Kangbo's understanding of the solitary transformation differs from that of Guo Xiang in the function of the "nothing". Guo Xiang said that the becoming and disappearing of objects is a change of the status of "being" (you), while the "nothing" (wu) is not part of the object's self. Yet Han Kangbo assumed that without a former status of "non-existence", the existence of things would not be possible. "Nothing", in his eyes, is a substantial part of the object's life cycle and their self.
In the field of politics, the "nothing" can be used to regulate what "is". Like all shapes (objects and matters) on earth have the Dao as their common ancestor, the masses of the people have to be led to a "unity" (yi 一). This means that if a ruler makes use of the patterns that the Dao gives to him, he will be able to bring peace and prosperity to his people. When the ruler has attained the highest essence (zhi jing 至精) of the Dao, there will be no chaos, even if no plans are made. When he has understood the perfectness of the changes (zhi bian 至變), his empire will be unified even if he has not made great plans. When he has reached the highest spirit (zhi shen 至神), all things will correctly correspond to each other, even if he does not move. The Yijing, that is likewise venerated by the Confucians and the Daoists, with its changing hexagrams is a helping tool to achieve these perfect conditions.
The most important writings of Han Kangbo are his commentary to the Book of Changes, the Zhouyi zhu 周易注, and his treatise Bianqianlun 辯謙論.